This application claims the priority of Korean Patent Application No. 2002-44504, filed on Jul. 27, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to an apparatus and method for identifying whether a memory card is inserted and constituting data for identifying the memory card using hardware.
2. Description of the Related Art
With the widespread use of digital communication devices or electronic devices for processing video data and music data, various types of memory cards, which store digital data, are distributed. A memory card mainly uses a flash memory and a SmartMedia by Japanese Toshiba, a MemoryStick by Japanese Sony, a CompactFlash by U.S. Sandisk, a MultiMedia Card and a Secure Digital Card jointly developed by U.S. Sandisk and German Siemens, and the like are standardized as such a memory card. Such a memory card is a recording medium, which is used in various types of portable electronic devices such as a digital camera, an MP3 player, a handheld personal computer (HPC), a personal digital assistant (PDA), a portable phone, or the like. The memory card is a kind of digital data memory device, the application field of which is increasingly expanding.
As the use of memories increases with the use of portable devices, the use of extendable memories increases compared with memories built into the portable devices. This is advantageous to a developer in terms of reducing the unit cost of a developed product and to a user in terms of easily expanding memories.
In order to follow the above trend, the use of various types of devices, such as a Compactflash, a Secure Digital (SD)/MultiMedia card, or the like, increases. Also, a dual multimedia card has several merits such as having the small size and transmitting high-speed data, and thus the use of the dual multimedia card increases.
The greatest advantage of a conventional multimedia card is to be capable of connecting up to 30 cards at once. Nevertheless, a portable product may actually have only one slot due to the limitation in the size thereof. One or more slots in the portable product may increase the size of the portable product. In other words, since it is actually impossible for a portable device to mount 30 cards as specified in the memory card specification, most portable devices have one slot and may expand by adding a maximum of one more card. Accordingly, a series of processes of identifying several cards in the memory card specification are not necessary. Also, in an event that a card is no longer inserted in a slot while accessing (mainly reading/writing) the card, information on the card's being out of the slot cannot be identified in a host. Thus, the reliability of the controlling of the host is uncertain.